Heavy duty brake



p 1941 A. R. MAIER 2,257,722 HEAVY DUTY BRAKE Filed July 27, 1959 3Sheets-Sheet 2 #0 0 5; E. MH/Ee Hi5 A RNEY.

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P 0, 1941. A. R. MAIER HEAVY DLW'Y BRAKE Filed July 27, 1959 PatentedSept. 30, 1941 HEAVY DUTY nasxa' August R. Maier, Dallas, Tex asslgnorto Oil- Well Supply Company, a corporation of New Jersey Applicationiuly27, 1939, Serial No. 286,902

13 Claims.

This invention relates to improvements in brakes and provides meanseffective to exert a smooth and uniform braking action on the coactingelements used throughout substantially the entire braking surfacethereof. limited thereto, the invention is peculiarly well suited forincorporation in high speed and heavy duty brakes.

Among the'objects of the invention are: the provision of braking means,in contact with substantially the entire circumferential surface of thebrake drum; jointly acting flexible and nonflexible braking meanscoacting with the drum, coacting instrumentalities whereby the wearoccasioned by brake application is distributed substantially evenly toall parts thereof, thereby increasing materially the useful life of theparts;

braking mechanism which freely disengages when not in use; mechanism forbrakes capable of relatively high speeds, positive in action and simplein construction; a floatingly supported anchorage for certain ofthebraking elements arranged to permit the latter to find a naturalWhile not left of Figure 2, certain parts being broken away in theinterest of cleamess; and I Figure 7 is a composite perspective viewillustrating the chief component parts of the brake hand, brake shoe andnovel connections and supporting means thereof, several of the partsbeing disjoined to better illustrate the novel characteristics.

Referring in detail to the drawings, the invention is illustrated asapplying to a heavy duty power transmission unit such as used in the oilfields for drilling wells or operating hoisting equipment and the like.As shown, the shaft 10, which carries a pair of brake drums |2-l2,

seat on the brake drum; flexible and non-flexible braking elementshingedly connected and having a swivel connection with a floatinglysupported anchorage so that regardless of nonuniform wear cf brakelinings, the braking elements will seat uniformly on the brake drum inposition for uniform coaction therewith.

The above and further objects of the invention are attained byutilization of the construction and arrangement of the coacti'ng partshereinafter described and shown in the accompanying drawings. For acomplete disclosure of the invention, reference is to be made to thefollowing description, the accompanying drawings and the appendedclaims.

In the drawings:

Figure 1 is a plan of brake bodying the invention, certain guards shownin the other figures being omitted;

Figure 2 is a sectional elevation on the line II- -II of Figure 1, theparts being shown in the position they assume when the brake is inreleased; or non-braking position;

Figure 3 is an inverted sectional plan taken on the staggered lineIII-J11 of Figure 2;

Figure ,4 is a longitudinal section on line IV- IV of Fig re 1;

Figure 5 is a view similar to Figure 2 showing the parts in the positionthey assume when a braking force is applied;

Figure 6 is a front elevation of the parts as I equipment emfullyappear.

is mounted in bearings l4|4 secured to I-beams lB-li which in turn aremounted on base girders Ill. The brake drums I2--l2 illustrated arearranged in tandem and are in the form of annular rims of T-shaped crosssection, the respective radial flanges of which are bolted to annularflanges 22 of a hub element 24 which is keyed, as indicated at 26, tothe shaft ll.

The improved braking mechanism of the present invention employssubstantially duplicate elements for coaction with the tandem drums I2-, and this duplicate mechanism is supported from an equalizerwhichjointly supports floating anchorages for the respective brakingmechanisms, as will hereinafter more It is apparent, therefore, that inthemain a description of braking elements for coaction with one of thetandem drums l2 will sumce for both.

As best shown in Figures 6 and 7, there is 5 provided an equalizer 28which is.drilled at its joint 36 has a bearing portion 38 whose pivotalaxis, as represented-by the line X-X in Figure '7, is parallel to theaxis of rotation of the shaft in and is disposed at right angles to theaxis Y--Y of the pin 32.

The equalizer" is pivoted on the pin l0 whose axis A-A is perpendicularto the axis of the drum shaft ID. The equalizer supporting pin lllpasses through the jaws 42 of a bifurcated compound pivotal mounting,indicated generally at 44, which is pivotally supported on a pin 48whose axis 3-3 is parallel to the axis of the shaft Ill. The compoundpivotal mounting 44 is supported by its pin 46 between fixed bracketmembers 48 suitably secured to or made integral viewed from the front ofFigure 1 or from the I with the base girders II. From the constructiondescribed, it is apparent that. the compound pivotal mounting 44 isswingable on an axis axis at right angles to that of the drum. The

equalizer in turn supports the knuckle joints on axes whicharesubstantially at right angles to the axis of the drum. Each knucklejoint 36 supports a floating dead end anchorage 68 which in turnsupports coacting flexible and nonflexible braking elements for coactionwith a respective one of the brake drums I2. The means for supportingthe dead end anchorge -58 from the knuckle joint 36 comprises a U-shaped link having a bridge portion 52 which pivots on the axis X-X ofthe knuckle joint.

Extending upwardly from the bridge portion there are parallel linkportions 54-54 whose upper ends terminate in eyes 56- -56 for thereception of a bolt 58 whose axis c--c is parallel to the axis of thebrake drum. Thus the dead end anchorage is pivotally supported by theeyes of the link portions which in turn are fioa'tingly supported by theknuckle and equalizer connections previously referred to.

Depending downwardly from the anchorage 58 there is a lug 68 which has abearing hole 62 formed therein whose axis dd is disposed substantiallyperpendicular to the axis c-c of the bolt 58.

A swivel pin 64 pierces upwardly extending arms 66 of a fitting 68, thuspivotally mounting the fitting on the depending lug 68 of the dead endanchorage. The swivel pin 64 has a head portion I8 which is fastened bybolts I2 screwed into tapped holes I4 of the outermost arm of thefitting 68. The fitting has a curved base flange I6 which is riveted orotherwise secured to a flexible brake band I8. A non-flexible brakingelement in the form of a shoe 88 is connected to the band I8 by means ofa fulcrum pin 82 which passes through registering openings 84 and 86formed respectively in the hub portion 88 of the fitting and lugportions 98 of the shoe. As thus arranged, it is apparent that theflexible brake band I8 and the non-flexible shoe 88 are connected by thefitting 68 and supported jointly by the dead end anchorage 68 which inturn is fioatingly supported by the links and equalizer.

The combined parts are thus constructed and arranged to permit the brakelinings hereinafter referred to, to find their own seats on the brakedrum so thatan extremely smooth brake application is securable and sothat there will be no binding of the parts which would tend to causeuneven brake application and uneven wear on the linings. Otherwiseexpressed, the relative disposition of the several pivotal axes of thecooperating component parts of the connections between the shoe and theflexible band and the floating anchorage and its floating support,permits of a freedom of action whereby the respective linings of thebrake elementsseat in an unrestrained manner on the surface of the brakemember I88. A spring I82 is disposed between the portion 88 of theguardand a washer "4, which is adjustably positioned on the bolt bymeans of a nut I86. As thus arranged, the spring normally tends toyieldingly position the brake in release position; that is, to urgetheanchorage and fulcrum pin 82 away from the surface of the brake drum.

The brake band I8 and the linings thereof, in the embodiment of theinvention illustrated, surround approximately three-fourths of thecircumference of the brake drum and the brake shoe 88 and its liningssurround the remaining quadrant. Thus the described arrangement providesmeans whereby the braking friction can be exerted simultaneouslythroughout substantially the entire circumference of the brake drum.Hence wear is distributed over a maximum area with the advantage that agreat area is available to quickly dissipate the heat generated.

For Jointly contracting the flexible brake band I8- and the non-flexibleshoe 88 about the drum, the band is provided with a live end fitting I88 which is pivotally connected by a pin I I8 with a sleeve II 2adjustably secured on the threaded shank of a link II4 by means ofadjusting nuts H8. The link has a bifurcated head II6 which is connectedwith brake contracting means to bewith a link I28 which in turn isconnected by a pin I38 with a crank arm I32 secured to a rock shaft I34mounted in bearings I36. The rock shaft at one end carries a brakeactuating lever I38 which, when rocked counterclockwise, as indicated bythe arrow C, will tend to contract the band and shoe about the drum.Thus the shoe and band will be moved from the release position shown inFigure 2 to the brake application position shown in Figure 5. Becausethe various coacting component parts are floatingly supported withrespect to the drum, the linings on the band and shoe will freely andtruly seat on the drum surface quite regardless of any irregularity inwear occasioned by non-uniformity of fiber or grain structure of thebrake linings themselves.

When a brake application is made by rocking the lever I38 in theproperdirection, the floating anchorage will move toward the drum,overcomingthe yielding pressure of the spring I82 as will be understood.Upon release of the braking pressure, the spring will move both shoe andthe dead end of the band away from the drum. To facilitate release ofthe live end of the band, a spring I48 is provided, one end of whichengages a lug I42 formed on the head H2 and the other end of whichengages a hook I44 on the end of a bolt I46 which is adjustablypositioned, by means of a nut I48 which reacts against the uprightportion of a bracket I68 secured to any fixed part of the framework.

The guard I88 above referred to is fixedly secured, as shown, to fixedframe members I62 and I54-juxtaposed to the brake drum. A plurality ofbolts I56 carrying adjusting nuts I68 provide means for adjustablylimiting the outward'movement of the brake band upon release of braking1 pressure so that when the band comes to rest in release position, thevarious circumferential portions thereof may occupy predeterminedposlportions of the lining may be successively brought into coactionwith the brake surface, thus providing for an extremely smooth andgradual brake application. There is also provided an adjusting bolt I60having adjusting nuts I62 thereon which are eifective to limit therelease position to which the floating anchorage is moved underinfluence of the brake releasing spring I 02. A similar adjusting boltI64 coacts with the live end fitting I08 to accurately control itsrelease position.

From the foregoing disclosure it is manifest that when a braking forceisapplied to the lever I", the shaft I34 will be rocked. This will turnthe two crank arms I32 mounted thereon in a counterclockwise direction.Each will act on a link I28 connected to a bell crank which in turn willmove the pins I22 and I24 relatively so as to cause a contractingmovement of the shoe 80 and band I8 about the drum. In the tandem brakearrangement described, the action of each braking assemblage on itsassociated drum will be self-compensating because of the fact that therespective dead end anchorage and mechanism associated with each drum issupported through the self-positioning equalizer and each anchorage forthe shoe and drum is in turn floatingly mounted from a knuckle jointcarried on the'equaiizer. Because the brake shoe and brake band for eachbrake has a swivel connection with the floating anchorage, it isapparent that the band and shoe for each respective brake is mounted forpractically universal movement so that it can find its own seat, all ofwhich results in extremely smooth braking action and distribution ofwear quite uniformly throughout the respective linings of the flexibleband and the non-flexible shoe. The great flexibility of the connectionswhich partake of pivotal movement about various angulariy disposed axeswill compensate for wear without bending or straining any of the parts,as well as to permit the brake linings to find their own seatsregardless of any inequality of wear in the operating connections.

An advantage which accrues from the use of a non-flexible shoe hingedlyconnected with a flexible band, is that in such a combination, for agiven diameter of brake drum, an increased braking action is securable.For example, assuming two drums having equal diameters and an equalnumber of square inches of brake lining area effective on each, the onehaving the novel combined shoe and flexible band arrangement describedcoacting therewith, wfll give a greater braking effect than the other,acted upon by a conventional single contracting band because the toggleaction exerted against the brake drum through the non-flexible shoe'andband will be greater than that which could be exerted by a singleflexible band.

While the embodiment of the invention illustrated has been described inconsiderable detail, it is to be understood that various modificationsand substitutions of equivalents may be made by those skilled in the artwithout departure from the invention as defined in the appended claims.

I claim:

1. A brake comprising a drum, a band having respective dead and live endportions, a brake shoe connected with the dead end portion thereof forcoaction with said drum, contracting means pivotally mounted on a fixedsupport adjacent the drum for actuating .said shoe and said band,connecting means between said shoe and said contracting means, ananchorage connected with said band and said v s hoe, a link supportingsaid anchorage with freedom for limited movement toward and from theface of said drum, and a knuckle member pivoted on an axis transverse tothe drum axis constituting a bearing for said link.

2. A brake comprising a drum, a band having respective dead and live endportions, a brake shoe connected with the dead end portion thereof forcoaction with said drum, contracting means for actuating said shoe andband, an anchorage connected with said band and shoe, a link preventingmovement of the anchorage in the direction of motion of the drum, acompound pivotal mounting supporting said link, means yieldinglysupporting said anchorage with freedom for limited radial movementrelative to the face of the drum, and means mounted independently of theshoe adjacent the drum .for contracting said shoe and band about thedrum.

3. A brake comprising a drum, a band having respective dead and live endfittings secured thereto, said band extending from the dead end fittingaround the drum in the direction of rotation thereof, a brake shoeconnected with the dead end fitting and extending in the oppositedirection, a knuckle member pivoted on an axis transverse to the drumaxis, a link pivoted thereto preventing movement of the anchorage in thedirection of motion of the drum, and means mounted independently of theshoe adjacent the drums for contracting said shoe and band about thedrum.

4. A brake comprising a drum, a flexible band and a non-flexible shoefor coaction therewith jointly surrounding substantially the entirecircumference of the drum, an anchorage jointly supporting the shoe andband with freedom for limited movement toward and from the drum, meansfor contracting the shoe and band about the drum, swivel means includinga pin whose axis is substantially at right angles to the axis of thedrum connecting the shoe and band to the anchorage, and means forfloatingly supporting the anchorage.

5. A brake comprising a drum, a band having respective dead and live andportions, a brake shoe connected with the dead end portion thereof forcoaction with said'drum, an anchorage to which said band and shoe arepivotally connected, and means floatingly supporting the anchorage withfreedom for limited turning movement about different axes transverse toone another so that the band and shoe automatically adjust themselvesfor proper coaction with the drum regardless of inequalities of wear.

6. A brake comprising a drum; a flexible band having a friction brakelining secured thereto, a non-flexible shoe, an anchorage, meansswiveled on the latter on an axis transverse to that of said drumpivotally connecting the band and shoe, means floatingly securing theanchorage against movement in the direction of rotation of said drum,and means for contracting said band and shoe about the drum.

7. A brake comprising a drum, a flexible band, a non-flexible shoe, ananchorage, a fitting pivoted thereto on an axis perpendicular to theroto said anchorage, and a compound pivotal mounting supporting saidlink.

8. A brake comprising a drum,a flexible band, a non-flexible shoe, ananchorage carrying a single member to which both the band and shoe arepivotally connected, a link for supporting the anchorage againstmovement in the direction of rotation of said drum yet with freedom forlimited movement toward and from the braking surface thereof, and acompound pivotal mounting supporting said link.

9. A brake comprising a drum, a flexible band, a non-flexible shoe, ananchorage to which both the band and shoe are pivotally connected, afitting swiveled thereto and fixedly attached to said band, pivotalmeans connecting the shoe to the band through said fitting, supportingmeans for said anchorage comprising a link pivoted thereto on an axissubstantially parallel to the drum axis, a knuckle joint providing onepivotal mounting about an axis also parallel to the drum axis andanother pivotal mounting about an axis substantially at right anglesthereto.

10. A brake comprising a drum, a flexible band, a non-flexible shoe, ananchorage to which both the band and shoe are pivotally connected,supporting means for supporting the anchorage comprising a link pivotedthereto on an axis parallel to the drum axis, a knuckle joint providingone pivotal mounting for the link about an axis parallel to the drumaxis, and another pivotal V band about the drum, a link pivotallyconnected mounting about an axis transverse thereto, a fixed guardsurrounding substantial portions of said band and shoe, means tending topull the band away from the drum, and a plurality of circumferentiallyspaced adjustable elements carried by the guard limiting the outwardmovement of spaced portions of the band.

11. A brake comprising a drum, a flexible band,

a non-flexible shoe, an anchorage to which both the band and shoe arepivotally connected, a link for supporting the anchorage againstmovement in the direction of rotation of said drum .yet with freedom forlimited movement toward and from the braking surface thereof, a knucklemember forming a pivotal bearing for said link and being mounted formovement about an axis transverse to the drum axis, a fixed guardsurrounding substantial portions of said band and shoe, means tending toretract said anchorage from said drum, and adjustable means carried bysaid guard limiting the retracting movement of said anchorage.

12. The apparatus of claim 10, including means tending to retract saidanchorage from said drum and adjustable means carried by said guardlimiting the retracting movement of said anchorage.

13. The apparatus of claim 10 wherein the adjustable elements comprisebolts screwable through the guard toward and from the brake drum.

AUGUST, R. MAIER.

